windows xp checking file system on c:

[pcguscar]

Hello, my sister has a vaio which she bought 2 years ago. It has Windows xp home edition. When she starts the computer, a blue screen appears with the following message:
Check file system C:
The type of file system is FAT32

One of your disks needs to be checked for consistency. You may cancel the disk check, but it is strongly recommended that you continue.
Volume Serial Number is 1871-CC6E

then it takes about 50 seconds to end the disk check. when it finally ends, the desktop background appears but there is no start bar nor any icons present. It is just the plain wall paper.There is no way I can turn off the computer normally (Ctrl+Alt+delete "task manager" is disabled). If I try to reinstall windows xp with the instalation kit, it does not work either (the same blue screen appears).
Does any one have any idea what the problem might be?
I will be very thankfull if somebody gives me an answer and a suggestion on how I can fix it.

I will appreciate your help.

[glc]

You need to run diagnostics on the hard drive - and I'd run ram diagnostics too.

Hard drive diags can be downloaded from the hard drive manufacturer, if you can't determine the manufacturer the Hitachi Drive Fitness Test will work on all brands.

You can download ram diags from www.memtest.org.